Can Ldap autheticate user's system login

I installed Zimbra 4.5 with all intergrated services on OpenSuse10.2 sucessfully, working greater than i expected, but I found the LDAP that comes with Zimbra only autheticate user's login when use emailbox,

for example: http://stx01a.roquette.cn, and then user input user name and password. that is working well. but I want LDAP also in charge of autheticating when user login to system. Could anyone give me idea? thanks in advance!

where to get?

Thanks a lot for you kindly reply, but where can I get the information about the 'zimbra ldaputils / samba admin extensions'?
in our company, less than thirty employees will use OpenSuse as client operating system,I installed Zimbra to be our email server, so in our enviroments, all pc will be running linux.